On Fri, Aug 26, 2022 at 09:14:09AM +0200, Roberto Sassu wrote:
On Fri, 2022-08-26 at 08:42 +0300, Jarkko Sakkinen wrote:
On Thu, Aug 18, 2022 at 05:29:23PM +0200, roberto.sassu@huaweicloud.com wrote:
From: Roberto Sassu roberto.sassu@huawei.com
In preparation for the patch that introduces the bpf_lookup_user_key() eBPF kfunc, move KEY_LOOKUP_ definitions to include/linux/key.h, to be able to validate the kfunc parameters.
Also, introduce key_lookup_flags_check() directly in include/linux/key.h, to reduce the risk that the check is not in sync with currently defined flags.
Missing the description what the heck this function even is.
Please, explain that.
Hi Jarkko
sorry, forgot to update the commit description. Will do it.
Also, the short subject is misleading because this *just* does not move flags.
Signed-off-by: Roberto Sassu roberto.sassu@huawei.com Reviewed-by: KP Singh kpsingh@kernel.org
include/linux/key.h | 11 +++++++++++ security/keys/internal.h | 2 -- 2 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/include/linux/key.h b/include/linux/key.h index 7febc4881363..b5bbae77a9e7 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -88,6 +88,17 @@ enum key_need_perm { KEY_DEFER_PERM_CHECK, /* Special: permission check is deferred */ }; +#define KEY_LOOKUP_CREATE 0x01 +#define KEY_LOOKUP_PARTIAL 0x02
/*
- Explain what the heck this function is.
*/
+static inline int key_lookup_flags_check(u64 flags) +{
- if (flags & ~(KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL))
return -EINVAL;- return 0;
+}
This is essentially a boolean function, right?
I.e. the implementation can be just:
!!(flags & ~(KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL))
Absolutely fine with that, if you prefer.
It can be either, it more depends on if a new function is needed in the first place.
E.g. if you are worried about maintaining you could just as well define a constant containing the mask, right?
Not even sure if this is needed in the first place, or would it be better just to open code it. How many call sites does it have anyway?
Daniel preferred to have this check here.
How many call sites?
BR, Jarkko